Pseudobalistes flavimarginatus (Rüppell, 1829 )
Yellowmargin triggerfish, 60cm

Pseudobalistes flavimarginatus is another large triggerfish that, like Balistoides viridescens, lays its eggs in a small hollow in the reef and may aggressively defend its nest against all comers, including divers who happen to stumble too close. I once watched three of these that had nests in a flat rubble channel at Pohnpei swarm around a diver who blundered into the area, and who had to wave his arms and legs to fend them off as he swam away. At Kwaj, these are most common on lagoon reefs.

Although these triggers are a bit shy, you can frequently see them from a distance digging for prey in the sand. The digging is interesting. It appears that they are blowing water in the sand to dig down into it. Of course, they have no lungs so their blowing would seem to be somewhat limited. I once thought they might be using their pectoral fins to "blow" sand away, but careful study of video clips appears to show this is not so.

The next two are larger juveniles starting to change to the adult color.

Juveniles are easier to approach than adults.

Even smaller.

Created 21 May 2012
Updated 7 January 2013

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